It is common practice in farming for dairy farms and ranches to collect and store animal waste in large holding containers, pits or outdoor lagoons for subsequent use as fertilizer. The animal waste or manure is typically in the form of a semi-solid or slurry. The storage reservoirs typically are sized to store a season's worth of accumulated manure, for example a winter's collection for disbursing as fertilizer in the spring, and often are sized to store a 150-180 day accumulation. The storage reservoirs can be above-ground storage containers, but are typically built below grade in the form of pits or lagoons. They generally are from 8-10 feet deep and vary in peripheral configuration from round, to rectangular to irregular in shape. The sidewalls of such reservoirs also vary, from vertical sidewalls to sloped or banked sidewalls. The reservoirs are generally uncovered, and can present a danger to one walking near them, and are therefore typically surrounded by appropriate fencing or barricade structures.
The reservoir is typically supplied through an underground conduit extending from a remotely located barn or building. Manure is generally forced through the conduit by means of a piston-type pump located in the barn, as for example described by the inventor's prior U.S. Pat. Nos. 3,687,311, 3,876,341 and 4,439,115. The reservoir contents are typically removed from the pit by means of pumps that pump the manure to a mobile tank that is subsequently moved to a fertilizing site where the manure is disbursed by appropriate spreaders.
Over a period of time, the manure within the reservoir settles and separates, leaving a lower sediment and an upper liquid portion. Floatable solids also typically rise to the surface, forming an upper layer or crust, entrapping the liquid portion between the upper crust and the bottom sediment in the reservoir. The liquid portion can readily be handled by vacuum or auger assisted vacuum pumps connected to vacuum tanks, such as disclosed in U.S. Pat. No. 4,661,046. Generally, however, more universal hydraulically driven impeller pumps are used to withdraw the manure from such reservoirs. Also, power agitators are typically placed in the reservoir from time to time to keep the manure from settling to a point such that a solid cake or layer of sludge is formed at the bottom. More modern pumps, such as that illustrated in U.S. Pat. No. 4,594,006 incorporate agitator apparatus in the form of augers and/or nozzle jet agitators which redirect a portion of the pumped slurry back into the reservoir to mix the sediment and liquid into a pumpable slurry.
Due to the "seasonal" emptying of the reservoir, and the need to be able to move a pump or agitator from location to location within the reservoir, such pumps and agitators used to empty and service the reservoir have typically been fairly portable. Further, it has been common to provide power to the pumps and agitators directly from a mechanical power take-off (PTO) or hydraulics of a tractor. One class of such pumps, such as illustrated in U.S. Pat. No. 4,661,046 requires the pump to be physically lifted, placed and secured in a proper pumping position relative to the reservoir. This type of pumping apparatus is suitable wherein a sleeve or other mounting structure is available for securing the pump in operative position relative to the reservoir. However, for large open pits or storage reservoirs, a larger pump having ease of mobility to and from the reservoir and for movement along the peripheral edges of the reservoir is preferred.
A number of portable pump and agitator structures generally configured for pulling behind and for positioning by a tractor are known in the art. Examples of such structures are shown, for example, in U.S. Pat. Nos. 3,905,725 and 4,594,006. Such structures are typically pivotally mounted to the axle assembly of the wheel structure used to transport the assembly such that the impeller head portion of the pump agitator is pivotally and/or telescopically lowered as an integral unit to its operative position within the reservoir. Often, however, such pump or agitator configurations are not "long" enough to be positioned far enough out into the reservoir to be effective or sufficiently efficient in emptying or agitating the reservoir contents. Further, in more shallow reservoirs, such pivotal apparatus which retains the support wheels at the upper edge of the reservoir, do not always provide that angular attitude for the pump which is operatively most efficient. There have been attempts such as illustrated in U.S. Pat. No. 5,100,303 to provide trailable pump and agitator assemblies wherein the support wheel structure for the apparatus is itself lowered into the reservoir. Such structures, however, are fairly complex and suffer the disadvantage of requiring submersion of the wheel assemblies into the corrosive material being pumped.
To the extent that the disclosures of the above referenced U.S. Pat. Nos. 3,687,311; 3,876,341; 3,905,725; 4,439,115; 4,594,006; 4,661,046 and 5,100,303 are required for providing a more complete description of the relevant art, they are hereby incorporated by reference.
While the above-described manure handling configurations provide in most cases adequate techniques for agitating and pumping the manure slurry from a reservoir, they are not always the most convenient or economical to use, and may require repeated time-consuming placement and movement maneuvers of the apparatus around the reservoir in order to effectively agitate and/or empty the reservoir. Since none of such agitator pump configurations known to date provide any degree of independent steerability, such movements of the assemblies require coordinated trailing maneuvering by the towing tractor, generally requiring the pump agitator to be physically removed from the reservoir and repositioned at a different location. Further, there are circumstances wherein there is limited access to the reservoir, or wherein it may be desireable to access the reservoir over an obstacle such as a fence, or wherein an above ground high-walled reservoir needs to be pumped and/or agitated. In such circumstances, the structures described above are generally unacceptable for performing the tasks.
While there are known pumping structures having flexible boom configurations suitable for pumping materials such as concrete and the like over obstacles or which use only vacuum pumping techniques, such pumps do not generally satisfy the other aforementioned desireable characteristics of pumps and agitators for forming and pumping of manure slurries from storage reservoirs. Most such known structures generally are expensive pumping configurations mounted on a truck bed or powered vehicle, and are simply not economically practical for use in a farming environment. The present invention addresses the aforementioned needs for an economical, efficient and easy to use apparatus for agitating and/or pumping slurry material from a storage reservoir in a manner that enables ease of maneuverability for readily placing the pump intake or agitation head at a desired position, that enables the pump or agitator to be directly powered from the tractor's auxiliary PTO and hydraulics, and that enables the pump or agitator to access the reservoir over physical obstacles such as fences or vertical reservoir walls. The present invention also provides a degree of improved reliability and economy by enabling cooling for the hydraulic power lines energizing the pump, by cooling such lines directly by the material being pumped.